A touch pad is a user interface allowing a user to touch a defined contact surface using his/her finger, a stylus pen, or the like, to simply and intuitively input a user manipulation. The touch pad has been used in various fields, such as a navigation device, a telematics terminal, a personal digital assistant (PDA), a laptop computer, a notebook computer, a smart phone, and the like.
The touch pad uses a touch recognizing technology such as resistive overlay, capacitive overlay, surface acoustic wave, infrared beam, or the like.
Since an existing touch pad recognizes a touch position at the moment at which a hand touches the touch pad, it does not provide a blind control. In order to solve this problem, a force-based touch pad sensing touch force to recognize user's search and input intentions has been suggested.
The force-based touch pad may recognize a touch input depending on a user's intention when an external factor hindering a touch operation of the user is not present. However, in the case in which the touch operation of the user is hindered by the external factor, the force-based touch pad generates a distorted touch input different from the user's intention to erroneously recognize the touch input.
For example, when the force-based touch pad is used in a vehicle, when a finger of the user applying pressure to the force-based touch pad is separated from the force-based touch pad due to vibrations generated while the vehicle passes through a speed bump when the user performs a touch input on the force-based touch pad, the force-based touch pad recognizes a touch input different from the user's intention.
In addition, when one or more of sensors provided in the force-based touch pad are erroneously operated, the force-based touch pad recognizes a touch input distorted from a user's intention.